KDJ is a retired Korean-American smasher who was known to be one of the best Sheik and Fox players in the United States in the 2006-2007 era. He continued to enter and placed decently at Melee tournaments after becoming a Marth main. He rose to fame by consistently placing in the top-8 of events during the MLG 2006 Pro Circuit, becoming known for his Sheik play. He was also known for his notorious money matching, in which he would repeatedly challenge top-level players to improve his own gameplay. KDJ shocked the Smash community when he defeated Ken 3-1, solidifying his position as one of the best Melee players in the world. During the 2006-2007 era, he was the only player known to have a positive record over Ken.
He first got into competitive play when training with Jinx, and then becoming a part of the Ninja Turtlez crew. His skill quickly increased, and after he surpassed all of the members of the crew, he began traveling to compete against the nation's best players. KDJ would go on to place well in several Melee tournaments over much of the next decade before he announced his retirement from competitive play in September 2015.
KDJ was also one of the 16 players to be invited to participate in the E3 2014-held Super Smash Bros. Invitational tournament to play Super Smash Bros. for Wii U, and was also one of the 7 players who had an episode dedicated to them in The Smash Brothers.
KDJ started his national career with a 9th place finish at MLG New York Opener 2006, only losing to Isai and Mew2King. He followed up by placing 4th at MLG Dallas 2006, 5th at MLG Anaheim 2006, and 7th at MLG Chicago 2006. He also placed 4th at Zero Challenge 2, notably defeating PC Chris in winners' bracket.
However, his breakout performance occurred at MLG Orlando 2006, where he made it to winners' finals by defeating both Mew2King and Ken. He lost to Azen and then to ChuDat in losers' finals, placing 3rd. At MLG New York Playoffs 2006, he defeated Mew2King before losing to Azen once again in winners' bracket, and then defeated Isai before losing to ChuDat in losers' bracket, placing 4th, and successfully qualifying for the MLG 2006 championship event.
KDJ eventually placed 2nd at MLG Las Vegas 2006. He defeated Mew2King and Ken in winners' bracket before losing to PC Chris in winners' finals, and then defeated Ken again in losers' finals before losing again to PC Chris in grand finals.
KDJ later attended Cataclysm 3, where he placed 2nd, defeating Forward, PC Chris, and ChuDat in losers' bracket after losing to ChuDat in winners' semis. He lost to Mew2King in grand finals. He also won MLG Long Island 2007 two months later, defeating ChuDat in winners' semis, and Mew2King in both winners' finals and grand finals. After not attending various nationals in the summer of 2007, he attended Viva La Smashtaclysm in November 2007, where he placed 3rd, losing to Azen in winners' quarters, and then sweeping through losers' bracket, defeating Chillin, Drephen, and Mew2King to make it to losers' finals, where he lost to ChuDat.
KDJ has won 3 out of 4 sets he has played against Ken, only dropping one set at Zero Challenge 2.
In early 2008, KDJ won the Worcester regional Nintendo sponsored Brawl tournament, playing as Sheik. His final match was against Compton of Deadly Alliance, who played Lucas. He then won the New York City Grand Championship of the Nintendo sponsored Brawl tournament, defeating DireVulcan of Deadly Alliance, who played Ike. However, he has not entered any Brawl tournaments or made an effort to develop his skill since.
In March 2009, KDJ placed 9th in both singles and doubles at Revival of Melee. It was his first time entering a major Melee tournament for over a year, since Viva La Smashtaclysm. After that, KDJ continued to play Melee locally, although not nearly to the same level as before.
On March 18th, 2014, Team Liquid, a StarCraft 2 and Dota 2 eSports organization, signed KDJ and Ken up for their Super Smash Bros. Melee team. KDJ has since made a comeback in the Melee community, resuming his career with decent placings at nationals, such as 17th at Apex 2014, 13th at SKTAR 3, 29th at MLG Anaheim 2014, 17th at CEO 2014, and 65th at EVO 2014.
On November 21st, 2014, KDJ was revealed to be the true player behind the "Karissa the Destroyer" prank at GameStop, using Diddy Kong. He missed much of the 2015 season because of hand injuries, and he would go on to conduct research on those types of injuries in the Smash community.
On September 28th, 2015, KDJ resigned from Team Liquid because of persistent wrist and hand pain, marking his retirement from competitive Smash. Apex 2015 ended up being his last tournament prior to his retirement, where he placed 33rd out of 1,037 entrants; KDJ had also planned on attending EVO 2015, but due to "several circumstances" that came up last minute, he did not attend.
On August 3rd, 2016, KDJ announced he would be entering singles at the nearby Shine 2016, making for his first appearance at a national in over a year. He cited improved feeling in his hands allowing him to participate and reconnect with the scene, if only on a "cameo appearance" basis.